1. Field of the Invention
The present invention relates generally to bumpers for motor vehicles and, more specifically, to a bumper system for a motor vehicle.
2. Description of the Related Art
It is known to provide a bumper system for a front end or rear end of a motor vehicle. For a front end of the motor vehicle, the bumper system typically includes a bumper beam extending transversely and secured to a forward end of a pair of front rails, which extend longitudinally and are spaced transversely. The bumper system also includes an energy absorber extending transversely and secured to the bumper beam. The bumper system may include a fascia disposed over and covering the energy absorber.
It is also known that the bumper system protects a body of the motor vehicle from low speed impact with an object through elastic or semi-plastic deformation of the energy absorber. It is further known that the bumper system is an absorber for high-speed impact with an object through major plastic deformation of the bumper beam.
Although the above bumper system has worked well, it suffers from the disadvantage that the bumper beam has a con stant cross-section which is either too weak to resist low speed impact at a center thereof or makes it too strong to absorb impact energy before the supporting vehicle rails collapse under the motor vehicle. Therefore, there is a need in the art to provide a bumper beam which will better balance both low speed impact protection and high speed energy absorption for a bumper system of a motor vehicle.
Accordingly, the present invention is a bumper system for a motor vehicle. The bumper system includes an energy absorber and a bumper beam interconnecting the energy absorber and vehicle structure and having a general B shape to absorb energy during an impact with an object by the bumper system.
One advantage of the present invention is that a new bumper system is provided for a motor vehicle. Another advantage of the present invention is that the bumper system includes a bumper beam made from a manufacturing process such as a roll formed process or an extrusion process with a generally xe2x80x9cBxe2x80x9d shaped cross-section which balances both low-speed impact and high-speed impact of the motor vehicle. Yet another advantage of the present invention is that the bumper system has an energy absorber to absorb the high-speed impact with an object and to protect the vehicle body from low-speed impact with an object. Still another advantage of the present invention is that the bumper system has a xe2x80x9cBxe2x80x9d shaped bumper beam to serve as an impact initiator to improve high-speed impact energy absorption efficiency. A further advantage of the present invention is that the bumper assembly has an inclined xe2x80x9cBxe2x80x9d bumper with specific geometry to provided uniform high-speed impact energy absorption. Yet a further advantage of the present invention is that the bumper system has a bumper beam that allows sequential collapse of inner walls to the collapse of upper/lower walls by partially supported rails of the motor vehicle.
Other features and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description when considered in connection with the accompanying drawings.